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  #1  
Old 08-03-2025, 10:49 PM
Davidpmcadam
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Location: Bermagui, Australia
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Horsehead and Centaurus A

For the first time in many months I has no moon, clear skied and calm winds. Managed to get enough suds for the image.

Processed in SIRIL and Affinity.

Equipment:
Mount: EQ6-pro
Telescope: SVBony 503 80mm ed with 0.8 reducer, FL 450 mm
Camera: ZWO 533 MC
Unguided (having problems with guiding)
29 X 90s subs
Attached Thumbnails
Click for full-size image (Horsehead Nebula Iceinspace.jpg)
113.3 KB111 views
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  #2  
Old 09-03-2025, 12:51 PM
Mickoid (Michael)
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That came out rather nicely, David. There are some weird gradients going on in the background which will be a result of your processing but as long as you don't zoom in too far, they are not too offensive when viewing the over all image. Great detail and colours too! Glad you finally had some good conditions to take those shots.

Last edited by Mickoid; 09-03-2025 at 03:38 PM.
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  #3  
Old 09-03-2025, 10:20 PM
Davidpmcadam
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Thanks Michael.
I think I need more data. With just 45 mins of data I over stretched the data to get the colours and brought in artefacts during processing.
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  #4  
Old 09-03-2025, 10:48 PM
Startrek (Martin)
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David,
Nice to see you post an image after quite a while, nice effort by the way
Looks like my old mount is still performing well for you which is great.
Happy to offer assistance with getting your guiding up and running if your using a guide scope not an OAG (email me if you wish )
Well done !!

Martin
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  #5  
Old 10-03-2025, 09:10 PM
Davidpmcadam
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Thanks Martin.
I will be taking up your offer.
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  #6  
Old 11-03-2025, 10:42 AM
Dekker (Derrick)
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Quote:
Originally Posted by Davidpmcadam View Post
I think I need more data. With just 45 mins of data I over stretched the data to get the colours and brought in artefacts during processing.
I don't think that's the problem. The image attached to your first post has been compressed to bring it under the attachment size limit, but that has seriously compromised the colour depth.


Do you have anywhere to host the original image that you can link to? The colours look good, and it would be great to see the image before it was squashed down to nothing.
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  #7  
Old 11-03-2025, 12:03 PM
Davidpmcadam
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Quote:
Originally Posted by Dekker View Post
I don't think that's the problem. The image attached to your first post has been compressed to bring it under the attachment size limit, but that has seriously compromised the colour depth.


Do you have anywhere to host the original image that you can link to? The colours look good, and it would be great to see the image before it was squashed down to nothing.
Derrick, I don't have anywhere to post the original file, eg Astrobin. I could sent you the file via private message (?). The file is 100MB.

David
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  #8  
Old 11-03-2025, 03:57 PM
Dekker (Derrick)
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Quote:
Originally Posted by Davidpmcadam View Post
Derrick, I don't have anywhere to post the original file, eg Astrobin. I could sent you the file via private message (?). The file is 100MB.

No, it won't send via pm or even email at that size. It's worth considering getting an Astrobin (or similar) account, but if that's not an option then you could use free software like GIMP or Paint.Net to compress the image as a JPEG under the 200kB limit yourself.


Paint.Net in particular is very good at this sort of thing, since you can adjust the compression parameters and get instant feedback on the final quality and file size. I have no doubt that you could get a much higher quality attachment doing it this way.
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  #9  
Old 11-03-2025, 04:52 PM
Cyberman (Rob)
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David, you can use Siril to save your image as a jpeg just under 2000KB (ie 2MB). You can then just upload this 2000KB (2MB) image to IIS. ISS will accept this 2MB image and IIS will compress this 2MB (2000KB) image to 200KB without losing too much data. When you save as jpeg in Siril a screen will come up asking you what quality(compression) you wish to save it as. Try 95% compression first up , but you will have to just keep trying different compressions until you get just under 2000KB ( ie 2MB). About 1900KB to 1999KB is good. It's not too onerous; you just replace the previous compressed image with the new compressed image.
Cheers, Rob
PS as you know, SIRIL is free

Last edited by Cyberman; 11-03-2025 at 05:06 PM.
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  #10  
Old 14-03-2025, 11:20 PM
Davidpmcadam
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Quote:
Originally Posted by Cyberman View Post
David, you can use Siril to save your image as a jpeg just under 2000KB (ie 2MB). You can then just upload this 2000KB (2MB) image to IIS. ISS will accept this 2MB image and IIS will compress this 2MB (2000KB) image to 200KB without losing too much data. When you save as jpeg in Siril a screen will come up asking you what quality(compression) you wish to save it as. Try 95% compression first up , but you will have to just keep trying different compressions until you get just under 2000KB ( ie 2MB). About 1900KB to 1999KB is good. It's not too onerous; you just replace the previous compressed image with the new compressed image.
Cheers, Rob
PS as you know, SIRIL is free
Rob
Thanks for your suggestion. I saved the image in Siril as a 1.9 MB JPG file and reposted here.
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Click for full-size image (horsehead_final_INS.jpg)
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  #11  
Old 15-03-2025, 07:18 PM
Cyberman (Rob)
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David that looks a lot better. More detail and not pixelated.
Rob
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